Pressurized fluid device

ABSTRACT

A portable pneumatic tool including an elongated housing having a rotatable output member supported thereon and adapted to have a wrench socket attached thereto. Lever means within the housing is interconnected with the output member through one-way clutch means and is oscillated by compressed air whereby to impart unidirectional rotation to the output member. In addition, the tool may be used as a hand-type wrench in which case the elongated housing operates as a handle and the one-way clutch means causes the output member to turn conjointly with the housing in one direction only.

O Unlted States Patent [151 3,673,921 Fritts et al. 1 July 4, 1972 [54]PRESSURIZED FLUID DEVICE FOREIGN PATENTS OR APPLICATIONS [72] Inventors:fil l A- ri g enix; Jerome 1. Re- 17,016 1890 Great Britain ..91/339 d,imonium,bo of Md.

7 Primary Examiner-Paul E. Maslousky [73] Asslgnee' 2: E E :11 6Manuhcmring Attorney-Leonard Bloom, Joseph R. Slotnik and Edward D. p y,9 [22] Filed: June 8, 1970 211 Appl. No.: 44,068 [57] ABSTRACT A ortableneumatic tool includin an elon ated housin h P at bl t b g d h g avmg aro a e outpu mem er supporte t ereon an "g." adapted to have a wrenchsocket attached thereto. Lever [58] Fieid 91/359 299 325 means withinthe housing is interconnected with the output member through one-wayclutch means and is oscillated by compressed air whereby to impartunidirectional rotation to [56] References cued the output member. Inaddition, the tool may be used as a UNITEDSTATES PATENTS hand-typewrench in which case the elongated housing operates as a handle and theone-way clutch means causes the l 1( g F f output member to turnconjointly with the housing in one 1 0mm direction onl 2,514,142 7/1950Reid ..91/339 y 3,460,347 8/1969 Kurtz ..9l/339 2 Claims, 7 DrawingFigures P'A'TENTEUJUL 41972 3. 673 9,21

sum 1 or a INVENTORS RUSSELL A. FRITTS BY RE 50L? 3 ATTORNEY PATENTEDJUL419. 2 v 3,678,921

sum 3 or 3 INVENTORS RUSSELL A. FRITTS ATTORNEY SUMMARY OF THE INVENTIONThe present invention is directed to a novel pressurized fluidmechanism, illustrated as a pneumatic mechanism, which includes ahousing having an oscillating lever disposed in a chamber therein.Passage means and valve means is provided in the housing to deliverpressurized air alternately to opposite sides of the chamber whereby tooscillate the lever therein. The oscillating lever may be connectedthrough a one-way clutch to an output member whereby to deliverunidirectional movement thereto.

Alternatively, a pair of chambers may be provided, each having anoscillating lever therein. In this case, passage and means is providedto oscillate the levers in opposite directions and each may be connectedby a one-way clutch to the output member whereby the output member issubstantially continuously driven in one direction.

Main objects of the present invention therefore are to provide a noveloscillating pressurized fluid motor and gearless mechanism adapted todeliver oscillatory or unidirectional rotary movement to an outputmember.

Further important objects of the present invention are to provide anovel motor and mechanism of the above character which is adapted foruse as a wrench (e.g., nut-runner) in which oscillatory motor action istransmitted to unidirectional movement through a one-way clutch,.andwhich is adapted for use in the nature of a hand ratchet wrench, inwhich case the motor housing functions as a handle and the one-wayclutch causes the handle and output member to turn conjointly in onedirection only.

Additional important objects of the present invention are to provide anovel motor and mechanism of the above character which is relativelyinexpensive to manufacture, rugged in construction, and reliable andefficient in use.

- BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective viewillustrating a pneumatic tool embodying a preferred form of the presentinvention;

FIG. 2 is an enlarged exploded view of the tool of FIG. 1;

FIG. 3 is an enlarged plan view partly broken away, of the tool ofFlG.1;

FIG. 4 is a sectional view of FIG. 3 taken along the line 4-4 thereof;

FIG. 5 is a schematic sequential view illustrating the movement of themotor parts;

FIG. 6 is a view similar to FIG. 4 but illustrating a modified form ofthe invention; and

FIG. 7 is a exploded perspective view of the structure of FIG. 6.

BROAD STATEMENT OF THE INVENTION Broadly described, the presentinvention relates to a pressu'rized fluid tool comprising a housing, anelongated fluid chamber formed in said housing and having an open end,lever means pivotally supported upon said housing and extending intosaid chamber, said lever means including an annular ring having anelongated paddle extending therefrom, said paddle extending into saidchamber substantially the full length thereof with said annular ringclosing the open end of said chamber, passage means including a pair ofpassages communicating with opposite sides of said chamber, valve meansin said passage means and constructed to communicate a pressure supplywith alternate ones of said passages and being operable in response topressure differential in said passages, whereby to open the higherpressure passage and close the lower pressure passage to the pressuresupply, exhaust port means in said chamber intermediate the sidesthereof and communicated with alternate ones of said passages as saidlever paddle oscillates, whereby said lever paddle moves in onedirection away from the first passage having the higher pressure andtoward a second passage having the lower pressure until said paddlepasses said exhaust port means, whereby said exhaust port means iscommunicated with said first passage and is closed to said secondpassage, whereby pressure in said first passage drops and the pressurein said second passage increases, whereby said valve means is shiftedand communicates said pressure supply to said second passage, wherebysaid lever paddle moves in the direction opposite said one direction.

DETAILED DESCRIPTION Referring now more specifically to the drawings, aportable pneumatic tool embodying a preferred form of the presentinvention is illustrated generally at 21 in FIGS. 1-4 and is seen toinclude an elongated body forming a motor housing 23 and comprising topand bottom covers 25, 27 and an intennediate spacer 29 arranged insandwich fashion and secured together by screws 31. Compressed air issupplied to the housing 23 through a conduit 33 to drive a motor withinthe housing 23 and rotates an output member 35 to which a socket 40 maybe attached in conventional wrench fashion. A throttle link 37 on thehousing 23 controls the flow of air from the conduit 33 to the motor.

Turning now to FIGS. 24, the pneumatic motor is formed by a pneumaticchamber 39 defined by an elongated cut-out 41 in the spacer 29 and bythe top and bottom covers 25, 27. A lolly-pop shaped lever 43 has anannular head 45 disposed between the top and bottom covers 25, 27 andclosing the end of the chamber 39. A paddle-like lever 47 extends fromthe annular head 45 into the chamber 39.

The lever head 45 is pivoted on the housing 23 between the covers 25, 27by suitable means. In this case, a drive shaft 49 is disposed within thelever head 45 and has reduced ends 51, 53 rotatably supported inopenings 55, 57 in the top and bottom covers 25, 27. The output member35 is keyed or otherwise secured to the shaft 49 and extends outwardlyof the housing 23 for attachment to the socket member 40 by a suitabledetent 5 0. A one-way clutch formed by a plurality of sprags 59 and apair of springs 61 is disposed between the shaft 49 and the head 45 andtransmits rotary movement from the head 45 to the shaft 49 in onedirection while allowing these parts to move relative to one another inthe other direction. For the parts shown, counterclockwise rotation ofthe head 45, as seen in FIGS. 1 & 2, causes the shaft 49 also to tumcounterclockwise. The head 45, however, can turn clockwise relative tothe shaft 49.

As shown in FIGS. 2-5, the pneumatic chamber 39 is substantially thesame length and height as the length and thickness of the lever paddle47. However, the width of the chamber 39 is somewhat greater than thewidth of the paddle 47 so as to allow pivotal movement of the lever 43about the center of the head 45. As shown, the end wall of the recess 41in the spacer 29 if formed substantially on a radius from the center ofthe head 45, and the side walls of this recess 41 lie in planes whichalso include the sides of the paddle 47 when at the sides of the chamber39.

Air pressure is admitted to the chamber 39 from the conduit 33 by way ofpassage means in the housing 23 and is controlled by valve means also inthe housing so that the lever 43 is rapidly oscillated about the axis ofthe head 45. Thus, the conduit 33 is connected by passages 60 and 62formed in a coupling formed in a coupling 64 to an inlet passage 61formed in the top cover 25. The passage 61 terminates in an inlet cavity63 formed by aligned recesses 65, 67 in the top and bottom covers 25, 27and an opening 69 in the spacer 29 and is normally closed by a ball 66engaged by a spring 68. The inlet cavity 63 is communicated by a passage70 in the spacer 29 with a valve cavity 71 formed by aligned recesses73, 75 in the top and bottom covers 25, 27 and a stepped opening 77 inthe spacer 29. A valve disk 79 is disposed in the opening 77 and,depending upon its position, communicates the pasage 70 with either amain passage 81 formed by grooves in the top cover 25 and upper sideofthe spacer 29, or a main passage 83 in the bottom cover 27 and lowerside of the spacer 29. A small plate 82 is disposed in the opening 77between the top cover 25 and the spacer 29 and defines an aperture 84equal in cross section to an aperture 86 at the lower side of theopening 77. An annular seal ring 80 is positioned between the plate 82and the top cover 25.

The main passages 81, 83 are communicated with opposite sides of boththe chamber 39 and the lever paddle 47. Thus, by supplying pressurizedair alternately to the main passages 81, 83, the lever 43 is oscillatedabout the axis of the head 45. Air is exhausted from the motor chamber39 to atmosphere through an exhaust port 85, a cavity 87 (formed by aplate 88 secured to bottom cover 27 by a screw 90), a port 89 in the topand bottom covers 25, 27, and a cavity 91 (formed by a plate 94 securedto top cover 25 by a screw 96), and an opening 93. This relatively longair discharge passage system allows the exhaust air to expand into apartially enclosed chamber and greatly reduces exhaust noise.

In use, the throttle link 37 is moved by a means of a trigger 95 tounseat the ball 66 whereupon pressurized fluid is admitted to passage61, inlet cavity 63, passage 70, and valve cavity 71. If the valve disk79 is positioned as shown in FIG. 4, pressurized air is admitted throughaperture 84 to recess 73, and flows to the motor chamber 39 by way ofmain passage 81. This causes the lever 43 to move in a counterclockwisedirection, as viewed in NO. 5. When the lever paddle 47 passes theexhaust port 85, the pressure in front of the moving paddle 47 begins torise rapidly while the pressure behind the paddle 47 rapidly drops.Since the top of the valve disk 79 (as seen in FIG. 4) is exposed to thepressure behind the paddle 47, and the bottom of the valve disk 79 isexposed to the pressure in front of the paddle 47 this rapid change inpressure lifts the valve disk 79 against the plate 82 so that now,pressurized air is delivered to the motor chamber 39 by way of mainpassage 83, After this shifting of the valve disk 79 occurs, momentumcarries the paddle 47 to the limit of its movement in a counterclockwisedirection (FIG. 5 A). However, now air is delivered to the motor chamber39 by way of main passage 83 and begins to push the paddle 47 in aclockwise direction as viewed in FIG. 5. Here, again, the same sequenceoccurs. Thus, until the paddle 47 reaches the exhaust port 85, airpressure behind the moving paddle 47 remains high since it is sealedfrom exhaust, while air pressure in front of the moving paddle 47remains low since it communicates with the atmosphere through port 85.Under these conditions, the pressure in recess 75 is somewhat higherthen that in recess 73 and the valve disk 79 remains against the plate82.

When paddle 47 passes exhaust port 85, air pressure behind the paddle 47drops rapidly since it now communicates with exhaust port 85, while thepressure in front of the moving paddle 47 rinses since it is now sealedfrom exhaust. This causes the valve disk 79 to move away from plate 82so that supply pressure is again delivered to motor chamber 39 by way ofmain passage 81. When the momentum of the moving paddle 47 is on ercomeby the build up of air pressure in front of it, the direct on of itsmovement is again reversed. Desirably, this occurs when the paddle 47approaches the side wall of motor chamber 39. Continued supply of air tothe motor chamber 39 thus oscillates the lever 43.

In the illustrated construction, the one-way clutch which includes thesprags 59 and springs 61 disposed within the lever head 45 and aroundthe shaft 49, converts the oscillatory movement of the lever 43 tocounterclockwise rotation of the shaft 49, as seen in FIG. 3. However,the sprags 59 allow the lever 43 to turn clockwise relative to the tothe shaft 49 as seen in this figure. Thus, when the wrench socket 40 isapplied to a workpiece (such as a threaded fastener) and the tool turnedon," the workpiece is turned in a clockwise direction (it being assumedthat that tool 21 is turned over from the FIG. 3 position). This willserve to tighten a right-handed fastener (or to loosen a left-handfastener). To then apply a further torque to a right hand fastener, thetool 21 with the socket 40 still in place on the fastener, can be usedlike 8 normal hund wrench. When so used, the housing 23 functions as ahandle and torque is transmitted to the fastener through the sprags 59when the handle (housing 23) is turned in a clockwise direction (whenlooking down on the top of FIG. 4). When the tool 21 is manually turnedin the opposite direction, the sprags 59 free wheel.

The particular type of tool referred to here is commonly called anut-runner tool and is used to run down and tighten threaded fasteners.Thus, powered operation quickly runs the fastener down to fingertightness, and final tightening is achieved by hand operation. Nutrunners of this type have in the past often employed a rotary drive, aright-angle gear train, and a one-way clutch assembly to obtain thedesired output. It will be appreciated that the present inventionobviates the need for any right-angle gear train and, in fact,eliminates the need for any gears at all. With the constructionillustrated and described above for FIGS. 1-5, the lever 43 can operateabout 24,000 cycles per minute and turns the socket 40 at a speed ofabout 1,000 revolutions per minute. This construction is decidedlyadvantageous when compared to the somewhat heavier, and more expensiveprior art versions which employ a right-angle gear transmission.

It will also be appreciated that the tool 21 can provide for drive ofthe socket 40 in the reverse direction, i.e., to loosen a right-hand ortighten a left-hand fastener, simply by attaching the socket 40 to theoutput member 35 at the other side of the housing 23. This is done byconstructing the output member 35 so that it can extend to this otherhousing side and attaching the socket 40 thereto, as shown in dottedlines in FIG. 4.

FIGS. 6 and 7 illustrate a modified version of the present invention. Inthis embodiment, the tool, generally illustrated at 109, employes a pairof levers which oscillate oppositely to one another. Thus, these leversmay be connected to the same output shaft through one-way clutch meansto transmit substantially continuous unidirectional rotary movementthereto.

As seen in FIGS. 6 and 7, this embodiment includes top and bottom covers111, 113, upper and lower spacers 115, 117, and a divider 119, all ofwhich are secured together in sandwich fashion by screws 121. A pair ofmotor chambers are defined by open recesses 123, in the spacers 115,117, respectively closed at their top and bottom by the top cover 111and spacer 119, and the spacer 119 and bottom cover 1 13, respectively.An upper lever 127 has an annular head 129 disposed between the topcover 111 and the spacer 119, and a paddle 131 extending into thechamber 123. A lower lever 133 has an annular head 135 disposed betweenthe spacer 119 and bottom cover 113, and a paddle 137 extending into thechamber 125. A pair of one-way clutches 139, 141 are disposed within thelever heads 129, 135 and surround an output shaft 143 which extendsthrough an opening in the spacer 119 and has reduced portions 142, 144joumalled in openings 146, 148 in the top and bottom covers 111, 113,respectively. An output member 145 is keyed in the shaft 143 and isadapted to extend outwardly therebeyond from either side thereof. Awrench socket 147 may be attached to the ex tending end of the member145 and is releasably retained thereon by detent means 149.

Pressurized air is supplied to the tool 109 from a source through aconduit 153. Like the embodiment of FIGS. 1-5, a throttle valveincluding a ball 154 and spring 156 is actuated by a throttle line (notshown) to admit pressurized air to the tool 109. When the throttle valveis opened, pressurized air is admitted to an inlet cavity 157 by way ofan inlet passage 159 in the top cover 111. The cavity 157 is connectedto a valve cavity 161 by cutout 163 in the divider 119, and the cavity161 is selectively communicated, through operation of a valve disk 162,with a main passageway 165 fonned in the top cover 111 and upper spacer115, or with a main pasageway 167 formed in the bottom cover 113 andlower spacer 117. The main passageway 165 communicates with one side ofthe motor chamber 123 and with the other side of the motor chamber 125by way of aligned apertures 169, 171, 173 in the upper spacer 115, thedivider 119, and lower spacer 117, respectively, and a passageway 175 inthe lower spacer 117 and bottom cover 113. Similarly, main passageway167 communicates with one side of the motor chamber 125 and with theother side of the motor chamber 123 by way of an aperture 177 in thelower spacer 117, and aperture 179 in the divider 119, an aperture 181in the upper spacer 115, and a passageway 183 in the top cover 1 l1 andupper spacer 115.

Thus, when air pressure is admitted to main passageway 165, it swingsthe lever 127 clockwise and the lever 133 counterclockwise as viewed inFIG. 7. Alternatively, with air pressure is admitted to passageway 167,the lever 127 swings counterclockwise and the lever 133 clockwise. Theone-way clutches 139, 141 are substantially identical, i.e., they areconstructed to transmit rotation to the output shaft 143 in onedirection only that direction being the same for both clutches. Sincethe levers 27, 133 pivot in opposite directions, one is always drivingthe shaft 143 while the other is free wheeling. The result is that theshaft 143 is driven substantially continuously in one direction.

The operation of this modification is substantially the same as thatdescribed for FIGS. 1-5 above. Thus, with the valve disk 162 in thelower position shown in FIG. 6, supply air is delivered to passageways165 and 175 and pivots the lever 127 clockwise and the lever 133counterclockwise. Air in front of the paddles 133, 137 is exhaustedthrough ports 185, 187. The air which exists through upper port 185 goesdirectly to atmosphere through an opening 189 formed between the topcover 1 1 1 and a removable plate 190, while the air from larger lowerport 187 enters an expansion cavity 191 between the bottom cover 113 anda removable plate 192, from where it passes through openings 193, 195,197, 199 in the bottom cover 113, the lower spacer 117, the divider 119,and upper spacer 115, respectively, and thence to the atmosphere throughopening 189. Like in the embodiment of FIGS. 1-5, the purpose of thisexpansion of exhaust air is to muffle the sound.

Before the paddles 131, 137 pass the exhaust ports 185, 187, airpressure behind the paddles is high while that in front of the paddlesis exhausted to the atmosphere through ports 185, 187. Thus, airpressure above the valve disk 162 is higher than that below it so thedisk remains in this position. However, when the paddles 131, 137 passthe ports 185, 187, air pressure behind the paddles drops rapidly whilethat in front rises correspondingly. Momentum carries the paddles 131,137 to the end of their strokes; however, this change in pressure withinthe tool 109 shifts the valve disk 162. Now, supply air is delivered topassageways 167, 183 and swings levers 127, 133 counterclockwise andclockwise respectively.

As in the embodiment of FIGS. 1-5, the direction of rotation imparted tothe socket 147 is reversed by mounting the socket on the other end ofthe output member 145, when the latter is positioned as shown in dottedlines in FIG. 6. Also, the tool 109 can function as a hand ratchetwrench, to for example, apply a final torque to a threaded fastener, byusing the elongated housing in the manner of a handle. The one-wayclutches 139, 141 cause the output member to turn conjointly with thetool housing in one direction while allowing the member 145 to freewheel" in the other direction.

While preferred embodiments of the present invention have beenillustrated and described in detail herein, it will be appreciated thatthe present invention transcends these embodiments and find use in thebroad class of pressurized fluid devices. Further, it will beappreciated that substitutions, modifications and omissions may be madethereto without departing from the spirit of the invention.

We claim:

1. A pressurized fluid tool comprising a housing, an elongated chamberformed in said housing and having an open end, lever means pivotallysupported upon said housing and extending into said chamber, said levermeans including an annular ring having an elongated paddle extendingtherefrom, said paddle extending into said chamber substantially thefull len thereof with said annular ring closing the open end of saichamber, passage means including a pair of passages communicating withopposite sides of said chamber, valve means in said passage means andconstructed to communicate a pressure supply with alternate ones of saidpassages and being operable in response to pressure differential in saidpassages, whereby to open the higher pressure passage and close thelower pressure passage to the pressure supply, exhaust port means insaid chamber intermediate the sides thereof and communicated withalternate ones of said passages as said lever paddle oscillates, wherebysaid lever paddle moves in one direction away from a first passagehaving the higher pressure and toward a second passage having the lowerpressure until said paddle passes said exhaust port means whereby saidexhaust port means is communicated with said first passage and is closedto said second passage, whereby pressure in said first passage drops andthe pressure in said second passage increases, whereby said valve meansis shifted and communicates said pressure supply to said second passage,whereby said lever paddle moves in the direction opposite said onedirection.

2. A tool as defined in claim 1 wherein said valve means includes acavity in said housing having a disk movably disposed therein, saidfirst and second passage passages with opposite ends of said cavity,said pressure supply communicating with said cavity intermediate saidends.

* i i I t v UNITED STATES PATENT OFFICE CERTIFICATE OF COECTION PatentNo. 3,673,921 I Dated July 4, 1972 Inventor(s)RuSSell A. Fritts, JeromeI. Rebold It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 61 delete formed in a coupling.

Column 3, line 34, after the numeral "83" the comma should be a period iColumn 3, line 50, the word rinses should be rises a Column 3, line 64,after the word "relative" remove to the.

Column 3, line 68, after the word "assumed" remove that.

Column 4, line 16, after the word "operate" insert at.

Column 5, line 5, the word "and" should be an.

Column 5, line 10 the word "with" should be when.

Column 6, line 47, after the word "second" remove passage and after theword "passages" insert communicating.

Signed and sealed this 6th day of February 1973..

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents FORM PO-1050 (1069) USCOMM-DC 60376-P69 fl' U 5. GOVERNMENTPRINTING OI'IICI: I!" 0-3584

1. A pressurized fluid tool comprising a housing, an elongated chamberformed in said housing and having an open end, lever means pivotallysupported upon said housing and extending into said chamber, said levermeans including an annular ring having an elongated paddle extendingtherefrom, said paddle extending into said chamber substantially thefull length thereof with said annular ring closing the open end of saidchamber, passage means including a pair of passages communicating withopposite sides of said chamber, valve means in said passage means andconstructed to communicate a pressure supply with alternate ones of saidpassages and being operable in response to pressure differential in saidpassages, whereby to open the higher pressure passage and close thelower pressure passage to the pressure supply, exhaust port means insaid chamber intermediate the sides thereof and communicated withalternate ones of said passages as said lever paddle oscillates, wherebysaid lever paddle moves in one direction away from a first passagehaving the higher pressure and toward a second passage having the lowerpressure until said paddle passes said exhaust port means whereby saidexhaust port means is communicated with said first passage and is closedto said second passage, whereby pressure in said first passage drops andthe pressure in said second passage increases, whereby said valve meansis shifted and communicates said pressure supply to said second passage,whereby said lever paddle moves in the direction opposite said onedirection.
 2. A tool as defined in claim 1 wherein said valve meansincludes a cavity in said housing having a disk movably disposedtherein, said first and second passage passages with opposite ends ofsaid cavity, said pressure supply communicating with said cavityintermediate said ends.